- Boost - lists.boost.org

[contract] C++11-like auto-functions
by Lorenzo Caminiti 02 Jul '12

02 Jul '12

Hello all, I'm thinking to expand Boost.Contract to support C++11-like auto-functions for C++03. The following macro: CONTRACT_FUNCTION( // f template( typename Left, typename Right ) auto (adding_func) ( (Left const&) left, (Right const&) right ) return(BOOT_TYPEOF_TPL(left + right)) ) { return left + right; } Would expand to something like the code below (but the main of course): #include <boost/typeof/typeof.hpp> #include <iostream> template< typename Left, typename Right > // TPARAMS(f) struct adding_func_result_123 { Left const& left; // PARAMS(f) Right const& right; // PARAMS(f) typedef BOOST_TYPEOF_TPL(left + right) // RESULT_TYPE(f) type ; }; template< typename Left, typename Right > typename adding_func_result_123<Left, Right>::type // TPARAMS(f) adding_func ( Left const& left, Right const& right ) { return left + right; } int main ( void ) { std::cout << adding_func(1, 2) << std::endl; return 0; } I got a ticket for it: https://sourceforge.net/apps/trac/contractpp/ticket/59 But I might implement it only after the Boost review... (Are C++11 auto-function really useful?) Thanks. --Lorenzo

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Re: [boost] Exact Decimal library
by Andrew Robb 02 Jul '12

02 Jul '12

Message-ID: <loom.20120702T032954-809(a)post.gmane.org> Hi Andrew, Would you be able to provide a short summary of the advantages, disadvantages or significant differences of your proposal versus the boost multi-precision library or the C++ std decimal proposal? Regards, Josh. The std decimal proposal seems to centre *IEEE 754-2008 * *hardware or slow software. My proposal is simple to make accounting safer to similar to SQL (NUMERIC and DECIMAL) using all hardware (including * *IEEE 754-2008 for IBM) but also in embedded processors.* * * *I *terminal brain cancer so I want to keep these out 'there'. http://ajrobb.livejournal.com/6918.html "I have expressive dyspepsia caused by terminal grade 4 glioblastoma mutiforme brain cancer" so writing and talking are difficult. Regards, Andrew Robb

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[thread/exception] trivial compile fix
by Tim Blechmann 02 Jul '12

02 Jul '12

the boost.lockfree testsuite requires the following trivial patch, which specifies the namespace for enable_if and disable_if. i've applied a similar patch to boost.parameter some time ago [1]. as it is trivial, is it ok to commit to trunk or shall i submit it to trac that the thread/exception maintainers can apply it? tim [1] https://svn.boost.org/trac/boost/changeset/75902

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thread & 1.50 issues
by Tim Blechmann 02 Jul '12

02 Jul '12

i came across two issues of boost.thread in 1.50. the first is a minor issue: the 1.50 tarball contains a libs/thread/src/shared_mutex.cpp source file, which includes boost/thread/v2/shared_mutex.hpp, which does not exist. by default it is not built, so it is not a big problem, but it is not really clean, either. the second issue is a bit more severe, as it is an undocumented API change: boost::TIME_UTC has been renamed to boost::TIME_UTC_ ... not sure what's the reason for it, but it breaks code that used the old symbol. this includes the boost-style threadpool library [1] ... so i wonder, is this change really needed? tim [1] http://threadpool.sourceforge.net

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Re: [boost] Exact Decimal library
by Andrew Robb 02 Jul '12

02 Jul '12

I am proposing a Boost library for exact decimal numbers https://docs.google.com/document/d/19n-E8Mu-0MWCcNt0pQnFi2Osq-qdMDW6aCBweMK…<https://docs.google.com/document/d/19n-E8Mu-0MWCcNt0pQnFi2Osq-qdMDW6aCBweMK…> Message-ID: <33DFA071B6DD6D4FB44851BDE4A7259317128A(a)xchmbbal503.ds.susq.com> Andrew Robb wrote: > > Introduction [snip] > Exact Decimal [snip lots of information and reference links] The reason for your post is unclear. Are you proposing a Boost library? Are you asking for an indication of interest?

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[geometry] distance on multiline with spherical coordinates
by Karsten Ahnert 01 Jul '12

01 Jul '12

Hi, the following code produces some strange results: typedef cs::spherical_equatorial< boost::geometry::degree > cs_type; typedef model::point< double , 2, cs_type > point_type; typedef model::linestring< point_type > linestring_type; point_type p( 1.0 , 1.0 ); linestring_type l; l.push_back( point_type( 0.0 , 2.0 ) ); l.push_back( point_type( 2.0 , 2.0 ) ); l.push_back( point_type( 4.0 , 2.0 ) ); cout << "Distance : " << boost::geometry::distance( p , l ) << endl; for( size_t i=1 ; i<l.size() ; ++i ) { linestring_type l_tmp; l_tmp.push_back( l[i-1] ); l_tmp.push_back( l[i] ); cout << "Point distance : " << boost::geometry::distance( p , l_tmp ) << endl; } The output is Distance : 0.0174373 Point distance : 0.0174586 Point distance : 0.0174373 This looks like a bug. The distance to the second segment can not be smaller than that to the first one. If I change the coordinate system to cartesian coordinates everything works as expected. Do I miss some major points?

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boost::locale throw exception std::bad_cast
by Alex Ivanov 01 Jul '12

01 Jul '12

Here is code sample: boost::locale::generator gen; std::string text="To be or not to be, that is the question." ssegment_index map(word,text.begin(),text.end(),gen("en_US.UTF-8")); last line throw exception std::bad_cast The tests was made on tthe hosts: Darwin mac-os 10.4.0 Darwin Kernel Version 10.4.0 (gcc version 4.2.1) Linux fedora 2.6.34.9-69.fc13.x86_64 (gcc version 4.8.0 ) Linux fedora 2.6.34.7-66.fc13.x86_64 (gcc version 4.4.5) Linux debian 2.6.32-5-amd64 (gcc version 4.7.0) with boost_1_50_0_beta1 How can I handle this? -- реклама ----------------------------------------------------------- Распродажа % модной одежды. Скидки до 70%. Количество ограниченно! Подробнее на сайте Bonprix http://goo.gl/1qLK1

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Formal Review Request: TypeErasure
by Steven Watanabe 30 Jun '12

30 Jun '12

AMDG I'd like to request a formal review of the TypeErasure library that I've posted about several times before here. The TypeErasure library is a generalization of boost::any and boost::function. It allows easy composition of arbitrary type erased operators. As an example of basic usage, we can simulate Boost.Any: any<mpl::vector<copy_constructible<>, typeid_<> > > x(10); int i = any_cast<int>(x); // i == 10 The library is available in the Boost Sandbox at http://svn.boost.org/svn/boost/sandbox/type_erasure/ You can download archives with pre-built documentation from http://sourceforge.net/projects/steven-watanabe.u/files/ Online documentation can be found here: http://steven_watanabe.users.sourceforge.net/type_erasure/libs/type_erasure/ In Christ, Steven Watanabe

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[exception] Boost.Exception and the C++11 standard
by Vicente J. Botet Escriba 30 Jun '12

30 Jun '12

Hi, I was wondering how Boost.Exception works on compilers supporting 18.8.5 Exception propagation. Can an exception thrown by a 3pp library by retrieved by boost::current_exception() by another library or application code? BTW, what is the degree of compliance of Boost.Exception respect to 18.8.5 Exception propagation and 18.8.6 nested_exception sections of the standard? Do you have a plan towards been C++11 compliant? Best, Vicente P.S. I know that I can ask myself the same kind of questions respect to Boost.Ratio/Chrono/Thread, but this should be covered on a separate thread ;-)

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Re: [boost] A GUI Library
by jinhao 30 Jun '12

30 Jun '12

On 2012/6/27 16:24, Klaim - Joël Lamotte wrote: > Hi, > > On Wed, Jun 27, 2012 at 2:55 PM, jinhao<cnjinhao(a)hotmail.com> wrote: > >> Is there any interest in this library? > > > My current understanding is that both Boost and the Standard C++ commitee > are interested in fully C++ library. > > However, the subject is complex and no library until now gathered > enough consensus to even get to the review stage of the boost process > (from memory). > You have to be ready for tons of feedback pointing problems. > > Now, I just read the websites but I have some questions: > > 1. can you write somewhere a big comparison between your library and other > popular GUI C++ libraries? Nana library is written though standard C++, this is a big difference between other libraries, as the brief mentioned, C++ idioms should works with a C++ library, and this is why the other popular GUI C++ libraries are not really C++ style at all. Secondly, this library can be work with a thread pool, it reduces the difficulty for threadization. > 2. if you want to submit your library to Boost, I think it would need to > be compatible (or maybe just use) boost.thread instead of your own solution I recognize that many ideas of my own solutions come from boost, not only boost.thread, there are boost.function, boost.any and so on, this is why I try to submit this library to boost and erase all my own solutions. > 3. the STR macro is a big problem, I think it will be a big source of > negative feedback. Now that we have boost.locale, would it be possible to > work with it instead? Somebody told me the problem before, I left the problem and searched a solution, I found many problem can be fixed by boost, and I rethink, can't keep on stealing ideas from boost. This is also why I try to submit this library to boost. > 4. I understand how you can build a GUI application in a way that is > mostly a list of statements. Does it means that you'd better organize your > windows/forms "types" as constructor functions? (ok found this that > partially answer my question: > http://nanaproject.wordpress.com/2012/01/31/idioms-and-insights-for-a-good-…) > 5. It is said that Nana is cross-platform, but I don't see any > demonstration of this (nevermind, I just found this: > http://nanaproject.wordpress.com/2012/05/16/tutorial-of-release-0-2-3/ ) > What are the target platforms? Target platforms should be Windows, Linux and Mac OS X, but now, it only works under Windows(GDI) and Linux(X11), the next is ready for Linux(framebuffer). A friend of mine asks for the support of framebuffer, so I leave the Mac OS X now. > 6. Should it work in non-graphic contexts like command-line only display? > (I'm thinking about GUI working in bash for example) Yes, like ncurses. But now it is not able to work in such environment. > 7. Is it thought to be easily extendable? For example, can I write myself > a new front-end implementation and plug it in? The library provide a general method to implement a customer widget, and supports external image-processing algorithm implementation (http://nanaproject.wordpress.com/2012/04/17/an-introduction-to-the-image-pr…) > 8. do you have an available example of complex application being built > with this library? Yes, but its language is Chinese, it is a stock software, a screenshot at http://sourceforge.net/projects/stdex The status of this library I give is alpha and the so library is not used widely. Best Regards! Jinhao

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